What causes a peach tree to split and leak pitch?
Certified GKH Gardening Expert
Splitting most commonly occurs in freezing weather. If the wound is not weeping or splitting further, then you should just leave it alone to heal on its own. If the split is widening or leaking as you say, you can try protective paper (sold at nurseries) to help hold it together while it heals. Do not cover the wound with tar or any other permanent substance as this can trap disease in the wound. It may also be attributed to peach tree borers. Here is an article that you may find helpful: https://www.gardeningknowhow.com/edible/fruits/peach/peach-tree-borer.htm